Let us stipulate that thriller writers can be divided into three categories. At the top are those -- Michael Connelly and George Pelecanos are good examples -- who write well-crafted, uncompromising novels that confront reality head-on -- straight, no chaser. At the other extreme we have novelists -- no names here, in the lingering spirit of Christmas -- who write what can generously be called fluff, deliberately dumb books filled with cliches, improbable events, inane dialogue and crowd-pleasing gimmicks that have nothing to do with the real world. In between, in perhaps the largest category, we have writers who give us generally intelligent and readable novels that nonetheless showcase bits of humor or color or melodrama designed to add to the book's commercial prospects. John Sandford's "Prey" series is the best example of this -- you can't quite take the books seriously, but they're wonderful fun. James Grippando isn't as talented as Sandford, but his new Jack Swyteck thriller belongs in this middle category. "When Darkness Falls" is well written, sometimes gripping and in some regards serious, but ultimately it raises the question of how much you can jazz up a story before it becomes hokey.

The novel has five main characters. Swyteck is an idealistic, half-Cuban Miami defense lawyer whose father was once Florida's governor. His best friend and "all-purpose assistant" is Theo Knight, a black man who was on death row, one hour from the electric chair, when Swyteck used DNA evidence to prove his innocence. (Swyteck's father, the governor, had approved the execution.) Alicia Mendoza is a gorgeous ("the dark, almond-shaped eyes, the full lips, the flawless olive skin") 27-year-old Miami cop whose father, originally from Argentina, is the city's mayor. Her lover, Vince Paulo, is the police department's best hostage negotiator but was blinded in the line of duty and has broken off their affair, although they still yearn for each other. Finally, the character who kicks the plot into action is a semi-deranged homeless man who calls himself Falcon.

At the outset, Falcon has climbed a lamppost atop a bridge and is threatening to jump unless he is permitted to talk to Alicia, the mayor's daughter. Instead, he is tricked into coming down and is arrested. Swyteck becomes his lawyer and discovers, when the question of bail arises, that his homeless client has $200,000 stashed in a safe-deposit box. Freed, the homeless man pulls a gun and abducts Swyteck and Theo. After their car crashes into a motel, Swyteck escapes, but Falcon takes Theo hostage along with three people in the motel. Two are teenage prostitutes, and the third is Walt the Weather Wizard, a local TV weatherman.

Falcon shoots two cops, whereupon the motel is surrounded by police and SWAT teams. This hostage crisis goes on for more than 200 pages, two-thirds of the novel. At times it's suspenseful, and at other times it's improbable. Falcon still wants to talk to Alicia, but the mayor forbids that. Vince, the blinded cop, is the chief negotiator, but Swyteck is on hand because Falcon semi-trusts him. Inside the barricaded motel room, Falcon paces about mumbling to himself and threatening to kill his hostages if they don't shut up. Theo, although bound hand and foot, fires back with demands and wisecracks, but Falcon never kills him.

In flashbacks, Falcon's memories take us to a prison where people are being tortured and killed in all too graphic scenes. It becomes clear that this is taking place some 30 years ago, during Argentina's Dirty War, when the military regime seized, tortured and often killed thousands of leftists, teachers, journalists, priests, nuns, union officials and students. These outrages led mothers of the "disappeared" to hold public protests, demanding information about their missing children. In one flashback, we see a pregnant woman give birth before she is taken to her death. At that point, the alert reader will ask, "Where is that child now?"

The hostage crisis lasts more than 18 hours. Outside the motel, the SWAT team and the negotiators are in conflict. Swyteck fears for Theo's life. Sparks fly between Vince and Alicia. She thinks his blindness has made him more sensitive and complex. He reflects on the beauty of rainfall to a blind man and his heightened senses: "He could feel the breeze on his face and smell the Laundromat down the street." Swyteck's abuela, his beloved Cuban grandmother, turns up with a picnic basket ("The papas fritas are deliciosa with the green-olive-and-garlic mojo") and urges him to share it with his friends.

And so it goes. A hostage crisis tied to long-ago political horror, which could have been a somber, even a powerful story, is enlivened -- or tarted up, depending on how you look at it -- by exotic characters, romance, local color and comic relief. Yet it remains a readable, better than average thriller. Perhaps the bottom line is this: "When Darkness Falls" has been selected by three book clubs. It's going to be successful in commercial terms, if less so in literary terms. But in most popular art -- movies, books, the theater -- if you seek a mass audience, a certain amount of compromise is part of the deal. Ultimately each reader must decide how much is too much.